A rising tide of phone banking fraud known as ‘vishing’ has prompted a leading MP to demand that banks take more action to combat the conmen and alert customers.

The fraud involves fake phone calls from criminals pretending to be banks and has led to tens of thousands of pounds being drained from customer accounts.

The British Bankers’ Association has agreed to an urgent meeting with Sam Gyimah, a former Goldman Sachs banker and now a Conservative whip, after he wrote to the BBA, as well as the chief executives of all Britain’s leading banks, calling for action.

Victims: Kathy and Jim Griffin from Surrey were taken in by a bogus caller who pretended to be from their bank, NatWest

Gyimah told The Mail on Sunday: ‘Someone has to take responsibility for this, to publicise the danger and make people aware.’

‘Vishing’ or ‘voice phishing’ was once unheard of, but in the past 12 months the Financial Ombudsman Service has dealt with hundreds of cases. Phishing is the acquisition of confidential information by underhand means.

The East Surrey MP became aware of the fraud after he was contacted by constituents who had lost money.

One retired couple lost £14,500, while another couple, Jim and Kathy Griffin, from Godstone, unknowingly handed over more than £42,000 from their account.

Jim, a self-employed electrician, received a call purporting to be from his bank, NatWest, on April 17, just before the Easter bank holiday weekend. The caller, who spoke with a Scottish accent, said suspicious activity had been spotted on Jim’s bank account.

He reassured Jim that there was nothing to worry about and that the bank would sort it out. But he suggested that if Jim had any other bank accounts he should get in touch with those banks as soon as possible. Jim had an account at Nationwide.

Campaigning MP: Sam Gyimah a former Goldman Sachs banker and now a Conservative whip, is battling on behalf of his constituents

‘Jim put the phone down, then picked it up again to make the call. He heard a dialling tone then phoned the number on the back of his bank card to get through to Nationwide,’ said Kathy.

‘He got through to what sounded like the switchboard at Nationwide, and was offered a number of options, before he got through to someone to speak to about his account. She asked him his name, date of birth, that kind of thing.’

He explained that NatWest had called him and suggested he call Nationwide. He did not realise that, instead of having reached Nationwide, he was speaking to the earlier caller, thanks to a glitch in the telephone system. It means that if a caller does not hang up, the line stays connected for up to two minutes.

When the victim redials they are reconnected to the previous caller, who is still on the line.

This time the fraudster on the end of the phone was a woman who pretended to be from Nationwide.

‘She said there was a payment for £11,000 due to come out of the account and asked if that was something we had set up, which it wasn’t, of course,’ said Kathy.

There was £40,000 in the account because the Griffins were considering buying a buy-to-let property and had borrowed money to do so.

‘She said she could set up a new account and advised him to transfer all of his money into it. She gave him an account number and sort code and was on the phone to him for about an hour and a quarter,’ said Kathy.

He transferred the money in lots of £10,000 at a time, the maximum that can be transferred without triggering money-laundering alarms.

In total, Jim transferred £42,300 to an account that turned out to be with Barclays. By the time the Griffins became suspicious it was the bank holiday weekend and they were unable to do anything about it until the following Tuesday

Kathy called the police, but was greeted only by a recorded message. ‘We tried to talk to the police several times, but they never came back to us,’ she said.

Gyimah intervened and contacted Nationwide and Barclays. Eventually, Nationwide agreed to reimburse the lost money. ‘I had to battle really hard to get Nationwide to agree to repay the money,’ he said.

The fraudsters could not be traced, but Gyimah said Barclays should also accept some responsibility.

‘Someone opened the account to receive the money in this fraud,’ he said. He wrote to BBA chief executive Anthony Browne last week calling for action and sent copies of the letter to the chief executives of Nationwide, Barclays, HSBC, Royal Bank of Scotland/Natwest, Lloyds, Santander and TSB. ‘It is unacceptable for banks to absolve themselves of responsibility for these types of scam,’ he wrote.

This weekend the BBA agreed to meet Gyimah and pledged to act to alert bank customers. ‘These awful crimes show that despite banks spending millions on sophisticated systems to protect customers from fraud and cyber crime, some ruthless criminals continue to target victims directly,’ said a spokesman.

‘The BBA will be launching a campaign later in the year to provide vital tips on what customers can do to avoid being caught out by these clever scams.’

The phone glitch that allows the trick that snared the Griffins is being rectified and BT told Gyimah that six million phone lines were no longer affected. But two-thirds of local exchanges will not be updated until next year, leaving millions of customers at risk.

A BT spokesman said: ‘We have cut the “holding the line open” time for calls made to about six million customer lines [about a third of BT’s local exchanges].

For the remaining exchanges, which are more complicated to change, it will take us longer. However, we expect that this will be completed within a year.’

A spokeswoman for Nationwide said the bank had made a goodwill gesture in the case of the Griffins, but it had been under no obligation to do so. ‘Nationwide has been doing a lot of work to educate members and we intend to do a lot more.’